Chemical Composition and Activities of Antioxidant Compounds in Red Pitaya Fruit (Hylocereus Sp.), and Effects on Glucose and Lipid Profile Level of Induced Hyperglycemia Rats
Abd Hadi, Nor Hayati (2006) Chemical Composition and Activities of Antioxidant Compounds in Red Pitaya Fruit (Hylocereus Sp.), and Effects on Glucose and Lipid Profile Level of Induced Hyperglycemia Rats. Masters thesis, Universiti Putra Malaysia.
The American Heart Association recommended a diet that includes five to nine servings of fruits and vegetables daily based on the combination of micronutrients, antioxidants,phytochemicals and dietary fiber in these foods.Epidemiology studies have indicated a negative relationship between fruit intake and various chronic diseases.This study therefore was designed to analysis the antioxidant vitamin composition,phenolic content of red pitaya fruit (Hylocereus sp.),antioxidant activity and free radical scavenging activity and effect on glucose and lipid profile levels of induced hyperglycemia rats.Thirty six male Sprague Dawley rats were randomly assigned into six groups.Hyperglycemia was induced in five of the six groups of rats by injection of streptozotocin (55 mg/ kg).The groups were normal (NO),hyperglycemia control (HK), hyperglycemia with 0.5% red pitaya supplementation (HP1), hyperglycemia with 0.87% red pitaya supplementation (HP2), hyperglycemia with 1.17% red pitaya supplementation (HP3) and hyperglycemia with glibenclamide treatment (HG).The study period was seven weeks. Results showed that crude fiber in red pitaya was 10.1 g/ 100 g dried sample while the lycopene content was 14.35 mg/ 100 g fresh sample. Results showed that the concentration of antioxidant vitamins in red pitaya were 120.13 μg/100 g freeze dried sample (Vitamin A),540.27 mg/100 g fresh sample (vitamin C) and 105.67 μg/100 g freeze dried sample (vitamin E).Results showed that the organic extract (76.19%, 72.90%) of red pitaya had higher antioxidant activity compared to aqueous extract (52.81%,47.79%) in both Ferik Thiosianat (FTC) and Thiobarbiturik Acid (TBA) methods.Red pitaya achieved the highest percentage of scavenging activity in an organic extract (70.13%) compared to an aqueous extract (47.13%). Phenolic content in organic extract of red pitaya was 46.06 ± 1.77 mg/100 g and 25.0 ± 0.87 mg/100 g in aqueous extract .After seven weeks of supplementing red pitaya and glibenclamide, red pitaya shows a potential in reducing blood glucose,cholesterol,triglycerides, LDL-c and malondialdehyde levels and increasing HDL-c levels and plasma antioxidants among the hyperglycemic rats.Results showed that the level of glucose reduced significantly about 29.87% (HP1),35.53% (HP2), 44.90% (HP3) and 27.3% (HG) respectively compared to baseline level (p<0.05).Total cholesterol reduced significantly (p<0.05) at 21.58% (HP1),23.08% (HP2), 27.27% (HP3) and 22.15% (HG). The triglyceride levels were also reduced significantly (p<0.05) about 35.7% (HP1), 37.2% (HP2), 39.8% (HP3) and 37.7% (HG) compared to the baseline level. The HP3 group showed the most increment in HDL-c level followed by HP2, HG and HP1 about 93.30%, 89.74%,89.47% and 76.32% respectively compared to baseline level. The LDL-c for the three supplemented groups decreased significantly about 62.16% (HP1), 70.59% (HP2), 78.65% (HP3) and 65.22% (HG) at the end of the study. The plasma antioxidant levels increased significantly about 18.63% (HP1), 24.34%(HP2),28.4% (HP3) and 23.09% (HG).The plasma malondialdehyde (MDA) decreased about 10.48% (HP1),16.04% (HP2), 20.75% (HP3) and 15.79% (HG) at the end of the study.It was found that HP3 group showed the higher decrement in blood glucose, cholesterol,triglycerides, LDL-c and malondialdehyde level and the highest increment in HDL-c levels and plasma antioxidant compared to the other groups.In conclusion,this study suggests that red pitaya have a potentialin reducing risk factors of diabetes mellitus disease if consumed in appropriate in the diet
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